We report here on a Japanese male infant with megalocornea-mental retardation (MMR) syndrome. He had megalocornea (corneal diameter: 13 mm) without glaucoma, developmental retardation, hypotonia, frontal bossing, high-arched palate, carp-like mouth, micrognathia, and delayed myelination. He seems to be included in Verloes type of the MMR syndrome.